3F-Talks: Functional Films and Fibres

We organize the 3F-Talks for participants from (textile/ fiber/ chemical) industry and academia to discuss latest developments in the view of their future practical importance. Intense discussions between speakers and participants are characteristic for this mini symposium, which is limited to a maximum of 80 participants. This year's focus will be on innovative 3D textile architectures and inspiring applications of additive manufacturing.

Thursday, April 28, 2016

17:30 Martin Möller

17:45 James Tarrier (Adidas AG)

adidas Speedfactory: new opportunities through automated manufacture

abstract follows soon

18:30 Leonid Ionov (University of Georgia, US)

3D microfabrication using biomimetic self - folding polymer films

Nature offers an enormous arsenal of ideas for the design of novel materials with superior properties and interesting behaviors. In particular, self-assembly and self-organization, which are fundamental to structure formation in nature, attract significant interest as promising concepts for the design of intelligent materials. Self-folding stimuli-responsive polymers are exemplary biomimetic materials and can be viewed as model systems for bioinspired actuation. Such polymeric objects, on one hand, mimic movement mechanisms in certain plant organs and, on the other hand, are able to self-organize and form complex 3D structures. These self-folding objects consist of two polymers with different properties and one of these polymers, the active one, must change its volume more than the other one in response to changes in the external signals such as temperature, pH or light. Because of this non-equal expansion of polymers, bilayer films are able, for example, to form tubes, capsules or more complex structures. Similar to origami, the self-folding polymeric films provide unique possibilities for the straightforward fabrication of highly complex 3D micro-structures with patterned inner and outer walls that cannot be achieved using other currently available technologies. In this contribution, we demonstrate that the external shape of polymer bicomponent systems is able to direct their folding in a sophisticated manner leading to highly complex hierarchical folding.

College of Engineering, College of Family and Consumer Sciences, University of Georgia, Athens, GA 30602, USA

Dinner and Get-Together

Friday, April 29, 2016

Fiber Engineering developed a new process FIM (Fiber Injection Molding) to build 3D fiber based parts with locally different densities according the specifications of the customer. In only one step FIM brings fibers in a final 3D shape and so it replaces semi products like sheets. This reduces material consumption up to 50% by eliminating the offcut of material and additionally saves the cutting process.

Yet there is still one shortage with respect of the requirements of the automotive industry for seat application. The automotive industry specifies compression testing by 5kg load on 100 cm² over a period of 22 hrs. at 70°C. Compression set <25% is allowed. While the FIM cushions perform well up to about 50°C, their performance at 70°C is average. At ITV the same is known from 3D Wavemaker webs. Thus in a common project the focus was laid on improvement of the binder fibers first. Then it turned out that the main fibers of PET are the bottleneck with their glass transition (Tg) of about 70°C – 80°C. Using PPS fibers (Tg 90°C) cushions with good results (compression set < 25% at volume weight < 40 kg/m³) could be achieved. The disadvantage of PPS fiber is their high costs. By modification of PET the onset of Tg could be increased above 80°C. Thus a good compression set is expected for these new fibers.

First FIM line for mass production was sold to a TIER1 in US for supplying parts for VW Passat.

Additive Manufacturing (AM) is a strongly growing technology promising customized products and components with geometries and functionalities that cannot be provided by conventional manufacturing technologies. Parts manufactured with present AM-processes are usually based on powders, liquids or molten polymer-strands and thus have isotropic characteristics. To make use of the excellent properties of high-performance fibres, several additive manufacturing approaches are developed at ITM.

The Net Shape Nonwoven (NSN) method has the potential to process short fibres in a range of 0.5mm to 4mm into three-dimensional structures of arbitrary geometry. Multiple biopolymers are used as a starting material or for functionalizing these nonwovens that are used as implants for in-situ Tissue Engineering. The medical textiles enable the ingrowth of cells due to the interconnecting pore spaces and the excellent ratio of surface to volume of fiber‑based components.

Another approach makes use of sized carbon-fibres having length ranging from 3mm up to 20mm. Mechanical and magnetic fibre orientation is used to generate near-net shape preforms with complex geometries and a defined anisotropic fiber direction. The preforms are used for the further processing to C/C-SiC ceramics that possess increased bending strength compared to the state of the art short fiber reinforced C/C-SiC ceramics with an isotropic fiber alignment.

9:50 Philipp Huber (ITA Aachen)

Categorization of 3-dimension textile structures and applications

Institut für Textiltechnik (ITA) der RWTH Aachen University

In recent years, research into 3-dimensional textiles and their application has increased significantly. Different textile structures have been utilized by a variety of industries like aerospace, automotive, construction and medical. However there is still a deficit in knowledge and experience of manufacturers concerning the requirements of the final product. The end-user on the other hand often lacks knowledge about the advanced textile processes and their possibilities.

This presentation will give a short review of the 3-dimensional textiles structures at the Institut für Textiltechnik (ITA) der RWTH Aachen University and their production processes. The main properties and typical applications of woven, knitted and warp knitted fabrics as well as braided 3-dimensional structures will be shown together with typical machinery for their production.

10:15 Markus Hildebrandt (IKV Aachen)

Processes for individualized and additive production of fibre reinforced plastic parts

The series production of technical products in large volumes is being influenced today more than ever by the increasing diversification of the products. The customer's wish for individual, function-integrated products as well as low prices is presenting manufacturers with mounting challenges in the fields of production development, process flexibility and cost efficiency. This trend towards customisation can be met particularly well by fibre-reinforced plastics (FRP). FRP, for example, can be combined from a variety of fibre and matrix materials to produce a material specifically designed to meet the requirements. Apart from the many possibilities for customising the property spectrum, their excellent moulding properties also allow replication of complex product geometries. The development of flexible and also resource-efficient manufacturing technologies is of particular importance for the customised manufacture of high-quality functionalised FRP parts.

This presentation shows some approaches for individualised production for thermoplastic and thermoset composites. One approach for customised part manufacture is the 3D fibre spraying method. Here, three-dimensional preforms with locally adjustable properties are produced in one step from fibre rovings additively and virtually scrap-free. The fibre orientation and fibre length can be adapted during the process locally in the preform according to the part specifications. For part production, a new approach is presented for the individualisation and functionalisation of products based on thermoplastic FRP. For this, additively manufactured semi-finished parts are firmly joined with continuous fibre reinforced thermoplastic sheets in a combined forming and joining process.

Coffee Break

11:30 Paolo Bavaj (Henkel)

New material development as enabler for industrial 3D printingHenkel AG & Co. KGaA

With the introduction of a new systematic and unique New Business Development approach in 2012 we changed the mind-set to innovation in Henkel Adhesive Technologies. We are now able to develop businesses in markets and areas we have not been active before.

Industrial 3D Printing requires tailored materials with very special properties and particularly formulated for different applications. It also needs robust industrial printing equipment as well as the right software to steer the printing.

With our initiative in “3D Printing of Functional Prototypes” we are taking care about these industry needs and drive further global digitalization. This is only possible through a strong Innovation Ecosystem with well-established companies as well as start-ups as partners.

11:55 Holger Leonards (Fraunhofer ILT)

Digital Photonic Production (DPP) stands for future and customer-oriented production. The Fraunhofer ILT understands Digital Photonic Production as an integrated system – from the beam source to processing system and from material through the manufacturing process to the product itself. Laser-based production processes fulfill the market’s requirements for higher component complexity and individualization at simultaneously attractive costs. DPP forms the »spearhead of evolution« for promising production processes. The Fraunhofer Institute for Laser Technology ILT has significantly prepared the way for this trend by developing Selective Laser Melting (SLM) as well as laser polishing and new laser processes for micro-processing. As a fundamental element of DPP the additive manufacturing (AM) activities at Fraunhofer ILT will be presented by a general overview, current activities and future challenges in metal, ceramic and polymer processing. Additionally a brief insight into recently opened Innovation Center Digital Photonic Production at RWTH University will be given.

12:20 John Linkhorst (DWI, AVT Aachen)

Selective Laser Sintering and Laser Metal Deposition Welding are techniques that open new possibilities for prototyping high quality custom shaped electrodes. However, these techniques involve expensive machinery and costly safety measures.

Using Paste Extrusion Printing on our custom designed 3D printhead makes prototyping of electrochemical electrode systems cost-effective. The versatility of the printer allows for printing any metal or ceramic as well as composites of up to three materials.

We show different printed geometries with increasing complexity and the electrochemical activity of a 3D printed electrode assembly.

12:45 Alireza Borhani (TransLAB /US)

Flexible textile structures : Constituting a programmable environment

The use of emerging technologies such as 3D/4D printing and advances in materials science offer the possibility of designing the behavior of material, rather than simply shaping already existing material. In the quest for exploring an alternative approach to design material behaviors, Flexible Textile Structures yield new potential for establishing a profound foundation for such an endeavor. As a bio-inspired approach to materials production, Flexible Textile Structures rely on both their appearance and performance.

As an alternative way of perceiving the material world, Flexible Textile Structures mark a shift in attention from the formal to the material that relies on both the material appearance and performance. Flexible Textile Structures offer both flexibility and rigidity on demand, and provide insight into the near future of resources called programmable materials. By extending the possibilities of the digital realm into multifaceted material behaviors, Flexible Textile Structures can be a fertile research tool that leads to interdisciplinary collaborations in art, science, and engineering. By crossing the boundaries of various fields such as biology, material science, computation, the textile industry, and additive manufacturing, Flexible Textile Structures aim to highlight the search for a way of thinking about issues of adaptation, change, and performance in different fields of design. Through the adaptation of functions, configurations, or behaviors, Flexible Textile Structures promise new possibilities for programmable actuation, sensing and self-transformation. In a sense, power source-less, motor-less and wireless components transform into new shapes to adjust their properties when confronted with changes in temperature, pressure, or moisture.

TransLAB /US

Lunch Break

14:30 Karen Deleersnyder (Centexbel /BE)

3D printing on textiles as a new tool for customized fabrics

Additive Manufacturing (AM), to a broader public better known as 3D Printing, is one of the fastest evolving technologies of the last decade that has led to new possibilities in the production process. Nowadays, 3D Printing is mainly used to make full objects but the combination of 3D Printing techniques with conventional production techniques into a hybrid technology may also lead to technically and economically interesting innovations. More recently, 3D Printing has also attracted the textile industry for the production of some niche products. Due to limitations in materials and production speed, 3D Printing is not yet at a stage to replace conventional production techniques such as weaving & knitting. But for the textile industry, opportunities for mass-customisation could be seen by directly 3D Printing functionalised parts on conventionally large scale produced textiles.Centexbel is already some years evaluating the use of 3D Printing on a variety of materials (with main focus on textiles and plastic parts). In collaboration with some companies, small scale prototypes are developed to demonstrate the potential of 3D Printing as an additional production technique. Furthermore, new filaments for 3D Printing are also developed according to the need from industrial partners.3D Printing on textiles could be very helpful for the production of individualised smart and functional textiles. Some application domains include printing of tailormade reinforcements on textiles or specific connector parts that can avoid further assembly steps, the incorporation of smart devices in textiles, and printing with functionalised polymer materials.

14:55 Michael Korger (Hochschule Niederrhein)

Additive manufacturing for textile surface modification

3D printing counts as a flexible and quick prototyping and manufacturing process which has a great potential to become more and more important in addition to well-established technologies and production processes in the coming years. Combining 3D printing with textiles new possibilities of individual product and process design present themselves in textile and clothing industry. 3D printing offers new ways of textile surface functionalization using thermoplastic materials from hard (such as acrylonitrile butadiene styrene ABS, polylactide PLA, polyamide PA) to flexible (such as Soft PLA, thermoplastic elastomers TPE). Furthermore, using different material combinations multicomponent textiles can be produced which show new property profiles.

In this lecture FDM (fused deposition modeling) technology and its additional benefit for the textile and clothing sector including different investigations to functionalize textiles are presented. Focus of research was set on improving adhesiveness of the print on textile substrates. In this context in addition to 3D printer settings and different combinations of thermoplastic and textile materials the influences of textile physical and chemical surface properties (such as weaves and after plasma treatment or washing) were investigated.